Title Photodynamic Therapy (PDT) Should Be Considered a Useful Adjunct in the Debridement of Teeth with Persistent Endodontic Infection
Clinical Question In teeth needing non-surgical endodontic retreatment, does the use of adjunctive photodynamic therapy (PDT) result in greater bacterial reduction in comparison to traditional irrigation techniques?
Clinical Bottom Line PDT can be considered a useful adjunct in the debridement of teeth with persistent endodontic infection. This is supported by a systematic review and meta-analysis of the literature showing a statistically significant reduction in bacteria following PDT as compared to traditional irrigation techniques alone. The aim of endodontic therapy is a reduction of bacteria below a threshold for resolution of disease; these studies provide evidence to support the use of adjunctive techniques to reduce the number of bacteria contained within the root canal system during endodontic retreatment.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
35840008Nunes/2022288 patients from 10 studiesMeta-Analysis
Key resultsThis systematic review and meta-analysis included 10 prospective clinical trials. These studies utilized measurement of pre- and post-treatment colony forming units (CFU) to assess the magnitude of bacterial reduction. The results of the meta-analysis showed a statistically significant decline in bacteria when adjunctive photodynamic therapy was used as compared to traditional irrigation alone during endodontic retreatment (OR 0.15 [0.07-0.32], p<0.0001).
35917508Gerbi/2022In vitro bovine teethLaboratory study
Key resultsThis in vitro study used artificially produced Enterococcus faecalis biofilms in bovine teeth to compare the efficacy of photodynamic therapy (PDT), Er:YAG assisted laser irrigation, and traditional NaOCl needle irrigation. Their results showed PDT irrigation and Er:YAG+PDT produced the most significant reduction in E. faecalis biofilm (p<0.05), with no significant difference between those two groups.
Evidence Search ‘(Photodynamic Therapy) AND (Endodontic retreatment)’, ‘(Photodynamic Therapy) AND (Endodontic Retreatment) OR (E. faecalis)’
Comments on
The Evidence
The systematic review and meta-analysis completed by Nunes et al. in 2022 is a compelling piece of evidence in support of PDT for treatment of persistent endodontic infections. This review included 10 prospective clinical trials, all of which showed a significant decline in the number of bacteria within the root canal system following PDT. A limitation of this study is the relatively high heterogeneity among the included articles, which effects the confidence we can have in the results. The study by Gerbi et al. in 2022 provides an in vitro proof of concept. Their study demonstrates PDT is an effective tool to eradicate E. faecalis biofilm, which is thought to be one of the predominant microorganisms found in persistent endodontic infections. However, due to the nature of the study, it lacks internal and external validity. There have been numerous studies exploring the impact of PDT and many show a positive association with enhanced bacterial reduction. The limiting factor in making conclusive determinations is the heterogeneity inherent in the studies; there are numerous photosensitizers used and a number of wavelengths of activation which have not been standardized. The evidence compiled here supports the use of PDT to reduce microbial load within the root canal system, but more standardized studies will be required to truly elucidate the best clinical protocol.
Applicability These findings demonstrate the applicability of adjunctive photodynamic therapy in the reduction of bacteria within the root canal system - a finding which can be extrapolated to improved healing and better outcomes for patients. This is of importance within the endodontic community - to both endodontists and general dentists who may be performing retreatment procedures daily.
Specialty (Endodontics)
Keywords Endodontics, Endodontic Retreatment, Photodynamic Therapy
ID# 3502
Date of submission 11/26/2022
E-mail czernick@livemail.uthscsa.edu
Author Matthew Czernick
Co-author(s) Joelle Foster
Co-author(s) e-mail fosterj1@uthscsa.edu
Faculty mentor Dr. Ruparel DDS PhD
Faculty mentor e-mail ruparel@uthscsa.edu
   
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
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Comments and Evidence-Based Updates on the CAT
(FOR PRACTICING DENTISTS', FACULTY, RESIDENTS and/or STUDENTS COMMENTS ON PUBLISHED CATs)
None available